Papermaking machine



April 15, 1969 K. J. HEINZ ETAL PAPERMAKING MACHINE Filed Aug, 2, 196eimmuun LMUMM United States Patent Oce 3,438,295 Patented Apr. 15, 1969U.S. Cl. 83-98 3 Claims ABSTRACT F THE DISCLOSURE An air distributingdevice for a cutter of the type having a rotating knife which has ashearing action with respect to a stationary knife for shearing a webpassing over the stationary knife to form individual sheets, with theair distributing device being positioned below a web carrying curvedforming board which is positioned below the web carrying nip of a pairof feed rolls and the air distributing device having an upper curved webcarrying surface and being positioned to direct air on to the uppersurface of the stationary knife for blowing olf the leading end of theweb from the stationary knife just after a cut has occurred so that theweb may continue to move over the stationary knife without clogging thecutter.

The invention relates to paper converting apparatus and moreparticularly to cutters for webs of paper or other sheet material.

One type of cutter for such webs comprises a rotating knife which has ashearing action with respect to a stationary knife for shearing a webpassed over the stationary knife to form individual sheets. When such acutter is used with paper of a type that is lightweight, drapes easily,and is tacky due to a resin impregnation of the web, for example, theweb tends to stick on the stationary knife after being cut, so that thecutter is eventually clogged.

It is an object of the present invention to provide an improved cutterarrangement of this general type which comprises means for moving theleading end of the web off of the stationary knife just after a cut hasbeen made so that the web may continue to pass over the stationaryknife, even though the web may be of tacky material, and so that suchclogging of the cutter cannot occur.

In brief, the invention contemplates that an air distributor may beprovided to have an air outlet or discharge port immediately adjacent tothe stationary knife for blowing off the leading end of the web from thestationary knife just after a cut has occurred so that the web maycontinue to move over the stationary knife without clogging the cutter.

The invention consists of the novel constructions, arrangements anddevices to be hereinafter described and claimed, for carrying out theabove stated objects, and such other objects, as will be apparent fromthe following description of a preferred form of the invention,illustrated with reference to the accompanying drawing, wherein:

FIG. 1 is a partial, longitudinal sectional view of a cutter for sheetmaterial having an air distributor device for directing air to urge thesheet material in its intended path of movement; and,

FIG. 2 is a plan view of the air distributor device and taken from line2 2 of FIG. 1.

Like characters of reference designate like parts in the several views.

Referring now to FIG. l in particular, the cutter shown therein may beseen to comprise a bottom feed roll 10, a top feed roll 11 having a nipwith the roll 10, a pair of forming boards 12 and 13, a stationary knife14 disposed on and fixed with respect to a knife bed 15, and a rotatingknife 16. t

The two feed rolls 10 and 11, or either of them, may be drivinglyrotated so as to feed a web A of sheet material, such as paper, betweenthe rolls 10 and 11 and over the forming boards 12 and 13. The formingboards 12 and 13 have upper surfaces 12a and 13a, respectively, whichare rounded and are generally cylindrical, and these surfaces are sodisposed as to guide the web A on to and over the stationary knife 14.

The stationary knife 14 has a sharpened corner or edge 14a, and therotating knife 16 has a sharpened edge 16a that has a shearing actionwith respect to the edge 14a as the knife 16 is rotated. The knife 16 iscarried by any suitable rotor having a center of rotation at the point17, for example, so that the knife 16 has the shearing action withrespect to the knife 14 as just mentioned.

An air distributor 18 extends between the forming boards 12 and 13. Thedistributor 18 comprises an upper casing portion 18a and a lower casingportion 18b providing an air passage 19 between them. A supply pipe 20extends into the distributor, and the pipe 20 is provided with aplurality of spaced air discharge ports 20a along its length incommunication with the passage 19. The pipe 20 is located at the upperand relatively wide end of the air passage 19, and the distributor 18extends around and in close proximity to the cylindrical upperl surface13a of the forming board 13 and terminates with a relatively thindischarge port 19a adjacent to the upper, horizontally extending, planesurface 14b of the stationary knife 14. The upper and lower casingportions 18a and 18b are connected together at a plurality ofintermediate places by short, internal ribs 21 for the purpose ofholding the portions 18a and 18b fixed with respect to each other. Theends of the distributor 18 are sealed at 21a and 2lb.

A source 22 of air under pressure is connected through a conduit 23 withthe pipe 20, and a pressure regulator 24 and a pressure gauge 25 areconnected respectively in and to the conduit 23.

In operation, the web A passes between the rolls 10 and 11, and theserolls in rotating move the web A over the upper cylindrical surfaces 12aand 13a of the forming boards 12 and 13 and over the stationary knife14. The knife 16 is at the same time rotating about the center 17; and,for every revolution of the knife 16, its edge 16a passes over inshearing contact with the edge 14a of the knife 14 and shears off alength of the web A.

Particularly in the case in which the web A is a tacky material, such aspaper which is highly saturated with hot, partially cured resin, forexample, the cut end of the web A tends to adhere to the upperhorizontal surface 14b of the stationary knife 14 and clog the cutter.The cut end of the web A is thrown backwardly slightly on to the upperhorizontal surface 14b of the stationary knife 14 as a shearing cut isbeing made, and this action in particular tends to cause the end of theweb A to adhere to the upper horizontal surface 14b of the stationaryknife 14.

The air distributor 18 is provided in order to move the end of the web Aoff of the upper horizontal surface 14b of the stationary knife 14. Thedischarge port |19a of the passage 19 and the ends of the housingportions 18a and 18h are located immediately adjacent to and directlyabove the horizontal plane surface 14b with only a very slight spacing,such as 1A; inch, therebetween. Air is thus directed by the distributor18 on to the :surface 14b, and the air flows toward the left as seen atFIG. l to move the cut end of the web A off of the surface 14b in thisdirection just after a cut has been made by the rotating knife 16. Theweb A thus is moved to drape over the cutting edge 14a so that the web Amay continue its movement over this edge. It will be observed that thelower side edge of the forming board 13 extends into contact with theupper surface 14b of the stationary knife so that all of the air fiowingfrom the discharge port 19a of the passage 19 must flow to the left asseen in FIG. l against the web A so as to tend to move the web in thisdirection.

Since the web A may well be tacky, particularly if the web isimpregnated with hot, partially cured resin, the upper casing portion18a with which the web A may at times come into contact, is preferablymade of a material which tends to release such a tacky web. The casingportions 18a and 18b may actually constitute a single piece of materialwhich has been folded about the pipe l for ease of construction, andthus the materials of the housing portions 18a and 18b may be the same.Materials that have been found satisfactory for releasing tacky webs andwhich therefore are quite suitable for the distributor 18 are Teflon andsilicone rubber, for example; and, as will be apparent, other similarmaterials which tend to release from tacky surfaces may also be used. Inview of the fact that the distributor 18 extends from the pipe 20located beneath and between the forming boards 12 and 13, and since thedistributor 18 extends in close proximity to the upper cylindricalsurface 13a of the forming board 13, the air distributor 18 does notimpede the movement of the web A from the rolls 10 and 11 and is out ofthe path of web movement even thou-gh the end of the distributor islocated very close to the upper horizontal surface 14b of the stationaryknife 14.

The air distributor 18, extending in close proximity to the uppercylindrical surface 13a of the forming board 13, provides a flow of airwhich is evenly distributed for the entire length of the cut by theknife 16 on the knife 14, which may for example, be 60 inches. A largevolume of air flow need not be provided through the distributor 18 forit to be effective, and we have found that only 8 to 12 pounds persquare inch air pressure need be applied to the distributor and the flowof air may be at only about 200 feet per minute, for example, giving agentle moving action to the end of the web A when a cut has been made.The pipe 20, for example, may only have a one-half inch inside diameter,for example, and the discharge port 19a of the passage 19 defined by theupper and lower casing portions 18a and 18b may only be about 1/16 inchin thickness.

The distributor 18 advantageously constitutes a simple device fordistributing air in connection with the moving web A, acting to forcethe end of the web A from the upper horizontal knife surface 14b on toany sheet collecting device located beneath the knife bed 15, such asfor example, moving tapes (not shown). The ribs 21 hold the upper andlower casing portions 18a and 18b together so as to maintain the spacingof the casing portions uniform at the discharge port 19a of the passage|19 for the complete length of the distributor 18. Since the casingportions '18a and 18b are preferably constructed of material that allowsa tacky surface to slide over it, even though the web A may have tackysurfaces, the web may pass over the upper casing portion 18a withoutadhering to it even though the web may come into contact with the casingportion at times.

Our improved air distributor, particularly in connection with a cutter,thus allows a cutter to be effective with a sheet which is limp andplastic or resin impregnated and in which the resin is intentionally notfully cured, so that the sheet is limp, drapes easily, and has tackysurfaces. The distributor, since it need not be provided with a largequantity of air, gently blows the end of the web A off of the upperknife surface 14b at a critical position at which the web A wouldotherwise stick. The distributor 18 is of such construction that itdirects air evenly over the entire width of the web A, utilizing low airpressures and volumes. Even though the configuration and construction ofthe cutter, as illustrated, may tend to prevent the use of conventionalmeans of air distribution, the air distributor is of such constructionto allow this air distribution even though the upper surface 14b of theknife 14 may be considered to be a difficult position for theapplication of air; and, at the same time, the distributor 18 does notobstruct the path of the web A. The distributor 18, being curved andlong and thin provides air movement intimately at or near the shearingedges 14a and 16a.

We wish it to be understood that the invention is not to be limited tothe specific constructions and arrangements shown and described, exceptonly insofar as the claims may be so limited, as it will be understoodto those skilled in the art that changes may be made without departingfrom the principles of the invention.

We claim:

1. In a cutter, a stationary knife blade, a moving knife blade adaptedto move across the stationary knife blade to shear off a web of sheetmaterial between the two blades, said moving knife blade being mountedfor rotation about a center at one side of said stationary knife blade,a pair of feed rolls disposed on the other side of said stationary knifeblade for feeding a web across the stationary knife blade from thisside, the shearing edge of said stationary knife blade defining an edgeof a surface on the stationary knife blade toward which said movingknife blade moves in its movement, an air distributor for directing aflow of air across the shearing edge of said stationary knife blade soas to move the sheet material web out of contact with said stationaryblade and the distributor being arranged to direct the flow of air ontosaid surface so as to move the cut end of the web off of said surface,and a pair of forming boards having upper curved surfaces over which theweb may travel from said feed rolls to said stationary knife blade andsaid distributor being curved and extending across and in closeproximity to the one of said forming boards more adjacent to saidstationary knife blade.

2. In a cutter, a stationary knife blade, a moving knife blade adaptedto move across the stationary knife blade to shear off a web of sheetmaterial between the two blades, said moving knife blade -being mountedfor rotation about a -center at one side of said stationary knife blade,a pair of feed rolls disposed on the other side of said stationary knifeblade and having a nip between them which is located at a higher levelthan said center of rotation and said stationary knife blade so as tofeed a web across said stationary knife blade from this side, theshearing edge of said stationary knife blade defining an edge of anupper sufrace of the stationary knife blade toward which said movingknife -blade moves in its movement, and an air distributor extendinglengthwise of said stationary knife blade and having a curved uppersurface extending from a place below said nip to a place adjacent saidupper surface of the stationary knife blade so that the web passingthrough said nip may facilely pass over the air distributor and the airdistributor having its air outlet adjacent the upper surface of saidstationary knife blade so as to direct a iiow of air onto said surfaceso that the air from the distributor moves the cut end of the web off ofsaid surface.

3. In a cutter, a stationary knife blade, a moving knife blade adaptedto move across the stationary knife blade to shear off a web of sheetmaterial Ibetween the two blades, said moving knife blade being mountedfor rotation about a center at one side of said stationary knife blade,a pair of feed rolls disposed on the other side of said stationary knifefblade and having a nip between them which is located at a higher levelthan said center of rotation and said stationary knife blade so as tofeed a web across said stationary knife blade from this side, theshearing edge of said stationary knife blade defining an edge of anupper surface of the stationary knife blade toward which said movingknife `blade moves in its movement, a forming board having an uppercurved surface 5 located adjacent and below said nip and an airdistributor extending lengthwise lof said stationary knife blade andhaving a curved upper surface extending from a place below said formingboard to a place adjacent said upper surface of the stationary knife:blade so that the web passing through said nip may facilely pass overthe forming board and then over the air distributor to said stationaryblade, said air distributor having its air outlet adjacent the uppersurface of said stationary knife -blade so as to direct a. ow of aironto said surface so that the air from l0 the distributor moves the cutend of the web off of said surface.

References Cited UNITED STATES PATENTS 1,978,826 10/1934 Walton et al.83-402 2,219,682 10/1940 Doble 83-402 X 2,699,736 1/1955 Sticelber.3,143,016 8/1964 Obenshain 83-98 3,342,093 9/1967 `Billin'gsley 83-402JAMES M. MEISTER, Primary Examiner.

U.S. Cl. X.R.

